Fix x86-64 Baker's read barrier fast path for CheckCast.

Use an art::x86_64::Label instead of an
art::x86_64::NearLabel as end label when emitting code for a
HCheckCast instruction, as the range of the latter may
sometimes be too short when Baker's read barriers are
enabled.

Bug: 12687968
Change-Id: Ia9742dce65be7d4fb104688f3c4717b65df1fb54
7 files changed